Control for machine tools



May 16, 933- E. P. BURRELLEI AL CONTROL FOR MACHINE TOOLS Filed Dec. 5,1928 4 Sheets-Sheet l M M d W M y 16, 1933- E. P. BURRELL El AL CONTROLFOR MACHINE TOOLS Filed Dec. 5. 1928 4 Sheets-Sheet 2 L mm M May 16,1933- E. P. B URRELL El AL 1,908,835

CONTROL FOR MACHINE TOOLS Filed Dec. 5, 1928 4 Sheets-Sheet 3 My I Q I IQ I x a Q l7ZU7zfo/&

I 'immmw dm May 16, 1933.

E. P. BURRELL El AL CONTROL FOR MACHINE TOOLS Filed Dec. 5, 1928 w ful I4 Sheets-Sheet 4 Patented May 16, 1 933 common Fen monmn TOOLSApplication filed Decemberfi, 1928. Serial No. 323,822.

This invention relates to control levers for machine tools and hasespecial utility Whenapplied to the head-stock of alathe, though notnecessarily confined thereto, as Wlll be explained presently.

The invention, in one of its aspects, is applicable to a machine toolwherein a series of levers is required for clutching and unclutching andfor speed change purposes or equivalent functions, the object of theinvention, when considered from this aspect, being to so group orarrange the levers that they may be conveniently actuated by theoperator While standing in one position at the front of the machine. Inthis connection, there is a furtherobject which involves the applicationof two or more control levers in association with a single indicatingbracket or combined indicating and holding bracket which will indicateto the operator the movements to be imparted to the levers to obtaincertain predetermined results in so far as direction of rotation andspeed are concerned.

In another aspect, the invention has particular reference to theconstruction of a lever, such as a main control lever, and itsarrangement with respect to the holding bracket or equivalent device, toprovide automatic locking of the lever against unintentional movement byvibration or otherwise when the lever is in a given position and toprovide for the release of the lever by theweight of the operators handso that no conscious effort on-the part of the operator is required torelease it or to restore it to locked position.

The above and other objects are attained by the present inventionwhichmay be briefly summarized as consisting in certain novel combinationsand arrangements of parts and details of construction which will bedescribed in the specification and set forth in the appended claims.

In the accompanying sheets of drawings, we have shown the inventionapplied to the head-stock of a lathe, and in the drawings Fig. 1 is anelevational view of the head of the lathe, i. e., lookingtoward'the endof the spindle from the bottom of the sheet of Fig.

'2, the main the object being.

operating lever, which in this instance controls the clutch, being inits locked neutral position; Fig. 2 is a top plan view of the same,showing only the forward portion of the head; Fig. 3 is a transversesectional view of the same substantially along the irregular line 3-3 offragmentary sectional view substantially along the line 4-4 of Fig. 2;and Fig. 5 is a front view of a portion of the head, showing amodification in the grouping of the levers and in the construction andarrangement of the control lever, the parts being shown on a slightlyreduced scale.

Though the invention is not confined in its use to the head-stock of alathe, but may be used to advantage on other parts of a lathe and onother types of machine tools, it is especially useful, as stated above,when applied to the head-stock of a lathe and for that reason is soillustrated.

Referring now to the drawings and, first, to Figs. 1 to 4, representsgenerally the head-stock of a lathe which includes a work spindle 11,which, as usual, projects through and slightly beyond the front wall ofthe head-stock. In this instance, the spindle is designed to be drivenby a drive shaft 12 in the forward direction through shafts 13 and 14,sleeve 15 and shaft 16, with suitable gearingbetween them, and thespindle is designed to be driven in the reverse direction through anidler shaft 17 with suitable gearing which connects it to the shaft 13.A head-stock with driving and driven parts which are here illustratedsimply and conventionally is well known and therefore a furtherdescription is unnecessary. The connection with the drive shaft 12 forboth forward and reverse rotation of the work spindle is, in thisinstance, controlled through a double-acting clutch on the drive shaft12. The operative part of the clutch, in the form of a cone, is shown at18in Figs. 2 and '3, this cone in this instance being shifted in eitherdirection by a clutch shifting member 19 which is slidable on a rod 20supported by the top plate of the head-stock.

To control the starting,

stopping and reversal of the spindle and to control the speed Fig. 2;Fig. 4 is a of the spindle in both directions, we have in v the front ofthe head-stock.

It might be here stated that the lever 21 is the main control leverwhich is shiftable in both directions from neutral position and" whichcontrols the clutch member 18 by shifting it in either direction fromcentral position into engagement with either of two companion clutchmembers so as to cause the spindle to be driven in either forward orreverse direction and by shifting it to disengaged position to stop therotation of the spindle, the lever then being in neutral position. Theother levers are in this instance designed to control the various speedchanges of the work spindle by movement in both directions, these leversbeing usually operatively connected with speed change gears or car conesor clutches.

me features of the present invention involve the main control lever 21,but other features of the invention reside in the grouping of theseveral levers mentioned in connection with a single holding andindicating bracket 25 which, in the construction illustrated in-Figs. 1to 4, is sup orted on the top plate of the head-stock. lit willbe-observed that the main control lever 21 and the lever 23 extend overthis bracket and that the other two levers 22 and 24 extend through anopening 25 of the bracket. The levers which are designed to be movedback and forth over the bracket and the two levers which are designed tobe moved back and forth in the opening 25 of the bracket have indicatingpoints 26 which are designed to cooperate with suitable indicia 27 onthe bracket to enable the operator to manipulate the several levers toobtain desired results in the way .of the direction of drive and speedof rotation of the work spindle (see Fig. 4).

The lever 21 is pivotally connected at 28 to a lever bracket 29 which issuitably secured to the top of a rock shaft 30 which extends through thetop plate of the head-stock and at its lower end has fixed thereto anarm 31 which engages anarm of the clutch shifting member 19. The lever22 directly beneath lever 21 is fixed to a sleeve 32 which surrounds therock shaft 30 and at its lower end has attached thereto an arm 33 at thefree end of which is pivotally supported a shifting member 34 whichstraddles a suitable speed change member. A detent indicated at 35 maybe provided on the arm 33 to hold the arm and the parts connectedtherewith, as well as the speed change member controlled tions. Asimilar detent arranged in a similar manner may be employed inconnection with each of the levers 23 and 24.

The lever 23 is secured to the top of a rock shaft 36 which extends downthrough the top plate of the, head-stock similar to the rock shaft 30,and the other lever 24 is secured to a sleeve 37 (shown by dotted linesin Fig. 2) surrounding the rock shaft 36, similar to the sleeve 32. Therock shaft 36 and the surrounding sleeve 37 will have attached theretosuitable shifting arms which will operate on the speed change membersutilized in the drive of the work spindle. As these devices are notdirectly involved in the invention, it is deemed unnecessary toillustrate them.

Referring now to the lever 21 and the associated lever bracket29, itwill be observed from Figs. 1 and 3 that the lever bracket 29 isprovided with a pair of cars 38 which straddle the lever 21, these carsbeing located on the side of the axis of the rock shaft 30 opposite thaton which the lever 21 is pivoted to the lever bracket. Additionally, itwill be seen that the lever 21 is provided with an extension 39 whichprojects downwardly and toward the free end of the lever beneath adownturned flange '40 on the holding and in dicating bracket 25. Thisflange of the bracket has a notch 41 shown most clearly in Figs. 3 and4, this notch being slightly wider than the width of the lever extension39 and being so located that it will receive the lever extension 39 whenthe lever 21 is in neutral position. Additionally, the lever 21 isprovided with a plunger 42 pressed outwardly by a spring 43, the plungerand spring being in a socket formed in the lever and so arranged thatthefree end of the plunger bears agamst a surface 44 substantially midway othe ears 38 on the lever bracket 29, the function of the spring being toswing the lever upwardly about its pivot 28 when the lever is released.

By reason of the fact that the cars 38 straddle the lever 21, it isobvious that when the lever 21 is swung horizontally it will turn thelever bracket 29 and therefore the rock shaft 30 and the shifting. arm31 attached thereto. It will be seen also that, when the operator takeshis -hand from the lever 21 when the latter is in neutral position, thespring 43 and plunger 42 will swing the lever 21 upwardly about thepivot 28 so as to cause the extension 39 to engage in the notch 41 ofthe flange 40. Accordingly, the lever will be locked in neutral positionand will not be accidentally moved by vibration or like cause.

- Furthermore, the arrangement and proportioning of the parts and theeffect of the spring 43 are such that simply the weight of the oeratorshand, when he grasps the lever 21 to shift it, will be sufficientto lower the lever 21 and thereby disengage the extension levers 22, 23and 24 generally will be 39 from the notch 40 so that the only consciouseffort on the part of the operator will be that necessary to swing thelever 21 laterally in onedirecti n or the other, depending upon whetherthe work spindle is to be driven in a forward or in a reverse'direction. -IVhen the operator takes ver when it is in either operativeposition, the extension 39 will engage the lower'surface of the flange40, and when the operator again grasps the lever and moves it to neutralposition and then releases the lever, the

extension 39 will automatically come into lock ng engagement with thenotch of the ange.

Not only is the construction of lever 21 with its self-locking featurean important part of the invention, but we regard also .within the scopeof our invention the centralized arrangement of the several levers 21,22, 23 and 24 and the provision of a single holding and indicatingbracket associated and cooperating with these levers or with a part ofthem as shown in the modification illustrated in Fig. 5. One importantadvantage of the arrangement is simplicity of construction and ease ofoperation by reason of the fact that all levers can be manipulated whenthe operator is in a given position in front of the machine. It isunnecessary, as has been the case heretofore, for the operator to movefrom one position to another to reach the several operating levers.

In Fig. 4 the neutral position of lever 21 is shown by full lines andits two working positions by dotted lines and the other three are eachshown by full lines in' one working position and by dotted lines inanother working position.

When the invention is applied to the headstock of a lathe, the severallevers may and arranged as illustrated in Figs. 1 to 4 on top of thehead-stock so as to project substantially horizontally to the front ofthe head. However, this arrangement is not essential for the controllevers for part of them may be arranged on the front side of the head.In Fig. 5 we have shown an arrangement wherein the main control leverand one of the speed controlling levers are arranged on the front sideof the head, and two other speed control levers are arranged at the topof the head, the former projecting substantially vertically and thelatter substantially horizontally, with the portions of all levers whichare to be grasped by the operator at the front of the machine andsubstantially in vertical alignment.

In Fig. 5, 45 represents the head at the front of which are a maincontrol lever 46 and a speed control lever 47, both mounted coaxially,and at the top of the head are two speed control levers 48 and 49 alsomounted coaxially. The main control lever 46 is pivhis hand off the leh51 so that when the lever oted by a transverse 51 which in turn issecured to the outer end of a rock shaft 52 extending horizontallythrough the head, this rock shaft'having secured to its inner end aclutch controlling arm 53 connected to a horizontally disposed The speedcontrol lesleeve 54 which surs ifting member 53". ver 47 is secured to arounds the rock shaft 52 and which has secured to its inner end ashifting arm 55 connected to a horizontally disposed shift-ing, member55. 55 will beconnected member and speed change gears which in theconstruction illustrated will be arranged in a downward extension of thehead.

The lever 46 has an extension 46 which fits between a pair of ears 51 ofthe lever bracket 46 is swung to start or stop the rotation of the workspindle the lever bracket 51111161 the'rock shaft 52 will be actuated.This extension has a lip 46 which is engaged by a plunger 56 acted uponby a spring 57 in a socket of the lever bracket so that the spring andplunger will, as in the first instance, rock the lever on the pivot pin50 when the-lever is released. A combined holding and indicating bracket58 is mounted on the front of the head and so arranged with respect tothe levers 46 and 47 that the lever 46 extends along the outer side ofthe bracket and the lever 47 through an opening of the bracket. Theinner side of the lever 46 has an extension 46 which is adapted toengage in a notch 58 on the outer side of the bracket, the extension andnotch being so disposed that when the lever 46 is in neutral position(and is released by the operator) the lever 46 will be rocked by thespring. 57 so as to cause the extension to automatically engage in thenotch, thereby holding the lever against accidental movement byvibration or other cause.

= The speed control lever 48 is secured to the top of a verticallydisposed rock shaft 59 which extends down through the top of the headand its lower end has secured thereto a shifting arm 60. The lever 49 issecured to a sleeve 61 which surrounds rock shaft 59 and which hassecured to its lower end a shifting arm 62. The lever 48 projects overan indicating bracket 63 and the lever '49 through an opening of thebracket.

As before stated, the arrangement illustrated brings the outer oroperating ends of the levers at the front of the machine and insubstantially vertical alignment with one another when the levers are inneutral position. Therefore, with this arrangement, as with thearrangement first described, all four levers may be actuated by theoperator while standing in one position before the machine.

As to the main control lever 46, though it is normally locked to bracket58 against accidental movement when this lever is in neutral Theshifting members 53 and respectively to a clutch pin 50 to a leverbracket position, it can be disengaged from' the bracket without anyconscious effort on the part of the operator. To bringthis about, thespring 57 is of such strength that it will slightly more thanoverbalance the effect of gravity on the lever, but when the operatorshand is placed on the outturned outer end of the lever the weight of hishand will be sufficient to rock the lever about the pin 50 and disengageit from the bracket 58 so that, as in the first instance, the .onlyconscious effort on the part of the operator is that required to swingthe lever to the right or left to start the work spindle either inforward or reverse or to stop its rotation.

It will be seen, therefore, that with both arrangements, the oneillustrated in Figs. 1'

to 4 and the other in Fig. 5, the levers are disposed so as to beconvenient to the operator without making it necessary for him to changehis position to reach all the levers and at the same time there isattained that feature of safety which results from the automatic lockingof he main control lever against acci dental displacement in eitherdirection, along with the release of the lever without conscious efiorton the part of the operator so that it may be actuated by him. Thearrangement of the coaxially mounted levers at the front of the head andthe coaxially mounted levers at the top of the head, as shown in Fig. 5,specifically forms no part of the invention covered by the presentapplication, but constitutes the subject matter of a copendingapplication of John J. N. Van Hamersveld, Serial No. 514,649, filedFebruary 9, 1931.

While we have illustrated two forms of arrangements of the invention, wedo not desire to be confined to the precise details of construction andarrangements of parts, but aim in our claims to cover all modificationswhich do not involve a departure from the spirit and scope of theinvention. For example, the automatic locking and substan-,

tially automatic unlocking feature here shown applied to the maincontrol lever may, if desired, be applied also to other levers of thegroup. Furthermore, this same feature may be utilized to lock a lever ina working or operative position rather than in neutral position asherein illustrated. In addition, other changes of like nature may bemade without departing from the spirit and scope of the invention.

Having thus described our invention, we claim:

1. A control lever for machine tools comprising an outer lever member,an inner lever member to which said outer lever member is connected, thetwo lever members being arranged so as to swing together, said leverhaving a central neutral position and adapted to be swung therefrom inboth directions to working positions, a holding member adjacent theouter lever member and positioned sitions, a holding member arrangedadjacent the outer portion, a spring carried by the outer portion of thelever for causing it to automatically engage the holding member when itis in neutral position, and a second lever arranged to swing coaxiallyof the first. 3. The combination with the head of a lathe having a workspindle and variable speed driving means therefor, of a plurality ofpairs of levers for controlling the starting and stopping of tion ofrotation, and the speed thereof, said levers being arranged adjacent oneanother in a group with the operating portions of the levers at thefront of the head, and a holding bracket arranged adjacent all saidlevers.

4. The combination with the head of a lathe having a work spindletogether with means for driving it at a plurality of speeds and inopposite directions, of a main control lever for controlling thedirection of rotation, starting and stopping of the work spindle, aplurality of speed control levers associated with said main controllever and arranged so that the operating portions of all said levers arein a group at the front of the head, and a holding bracket arrangedadjacent all said levers.

5. A control for machine tools comprising a plurality of groups oflevers arranged adjacent each other, the levers of each group beingcoaxial, and a single indicating bracket arranlgpd between the levers ofeach group.

6. a control for machine tools, a plurality of control levers arrangedadjacent each other in two groups each having 00- axial levers, and abracket having a portion arranged between the levers of'both groups.

7.. In a control for machine tools, pairs of coaxially mounted controllevers, and a bracket arranged adjacent said levers so that one of thelevers of each pair will swing over the bracket and the other will swingthrough the bracket.

8. In a control for machine tools, a plurality of control leversarranged in groups having coaxial supports, one having a central neutralposition and being adapted to be. swung therefrom in both directions toworking positions, and a holding bracket arranged with a portion betweenthe levers so that some levers will swing'over said portion and otherlevers will swing under said portion, one of said levers composed ofpivotally conthe work spindle, the direcnected portions one adapted tointerlock with said bracket when the lever is in neutral position.

9. A control device for machine tools comprising a rotatable bracketadapted to be connected to a shaft, a lever pivoted at one end of thebracket and guided in the other end 7 of the bracket, a stationarybracket, said lever having an extension, means for moving said lever inone direction to engage said extension With said stationary bracket toform an interlock therewith, and means on said lever cooperating withsaid stationary bracket for limiting movement of the lever in theopposite direction.

10. A control device for a machine tool comprising a rotatable bracketadapted to be connected to a shaft and having forked portions at itsopposite ends, a lever pivoted to one of said portions and guided in theother of said portions, a stationary bracket, an extension on said leveradapted to interlock with said bracket, and a spring carried by saidlever for moving the same to interlocked position.

In testimony whereof, we hereunto aflix I our signatures.

EDWARD P. BURRELL. GEORGE W. DRAKE.

